Clinical Laboratory Core. The CLC comprises an analytical laboratory directed by Mr. T.B. Cooper and a molecular genetic studies laboratory directed by Dr. T. Conrad Gilliam, Head of the Columbia Genome Center. In the latter blood will be collected for genotyping from all Conte Center subjects and DNA will be extracted from postmortem brain tissues of suicides and controls. These samples will be tested for a series of candidate genes related to central serotonin metabolism and include the serotonin transporter, tryptophan hydroxylase and serotonin receptors 5HT/1A, 5HT/1D, 5HT/1E and 5HT2A. The Genome Center will be responsible for development and interpretation of the microarray assays to be run in postmortem brain samples from selected regions to detect differences in gene expression and identify new candidate genes. The promoter region of the 5-HTT from postmortem causes that are phenotypic extremes will be sequenced in a attempt to determine new functional polymorphisms. The analytical laboratory will be responsible for assay of neurotransmitters and metabolites (cortisol, prolactin, HIAA, HVA, MHPG, GABA and glutamate) and neuroendocrine measures (cortisol, prolactin, ACTH, and CRF) in CSF and brain tissue from patients, controls, non-human primates and rodents. Brain tissue samples are being screened for the presence of drugs which effect the serotonergic system. Similarly hair samples are screened for these same drugs to detect long term exposure (months or even years).